補(bu)償(chang)器(qi)習慣上(shang)也叫膨脹節，或伸(shen)縮(suo)節。由構(gou)成其工(gong)作主體的波(bo)紋管(guan)(guan)(guan)（一(yi)(yi)種彈性元件(jian)(jian)）和端管(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導管(guan)(guan)(guan)等附件(jian)(jian)組成。 屬于(yu)(yu)一(yi)(yi)種補(bu)償(chang)元件(jian)(jian)。利(li)用(yong)其工(gong)作主體波(bo)紋管(guan)(guan)(guan)的有效伸(shen)縮(suo)變形，以(yi)吸收管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容器(qi)等由熱脹冷縮(suo)等原(yuan)因而(er)產生的尺寸變化，或補(bu)償(chang)管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容器(qi)等的軸(zhou)向(xiang)(xiang)、橫向(xiang)(xiang)和角向(xiang)(xiang)位移。也可用(yong)于(yu)(yu)降噪減振。在(zai)現代(dai)工(gong)業(ye)中(zhong)用(yong)途廣泛。供(gong)熱上(shang)，為(wei)了防止供(gong)熱管(guan)(guan)(guan)道(dao)升溫時，由于(yu)(yu)熱伸(shen)長(chang)或溫度應力(li)而(er)引(yin)起管(guan)(guan)(guan)道(dao)變形或破壞，需要在(zai)管(guan)(guan)(guan)道(dao)上(shang)設置補(bu)償(chang)器(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)道(dao)的熱伸(shen)長(chang)，從(cong)而(er)減小管(guan)(guan)(guan)壁的應力(li)和作用(yong)在(zai)閥件(jian)(jian)或支(zhi)架(jia)結構(gou)上(shang)的作用(yong)力(li)。